Pharmaceutical combination of (e)-7-[4-(4-fluorophenyl)-6-isopropyl-2-[methyl(methylsulfonyl)amino]pyrimidin-5-yl] (3r,5s)-3,5-dihydroxyhept-6-enoic acid and candesartan

ABSTRACT

The present invention relates to a new use of a statin drug in the improvement of diabetic neuropathy, specifically in improving nerve conduction velocity and nerve blood flow in patients suffering diabetes, in particular to pharmaceutical combinations of the statin drug and other agents known to improve diabetic neuropathy such as an aldose reductase inhibitor (ARI), an angiotensin converting enzyme (ACE) inhibitor or an angiotensin II (AII) antagonist which combinations are useful in the prevention and treatment of the complications of diabetes

The present invention relates to a new use of a statin drug in theimprovement of diabetic neuropathy, specifically in improving nerveconduction velocity and nerve blood flow in patients suffering diabetes,in particular to pharmaceutical combinations of the statin drug andother agents known to improve diabetic neuropathy such as an aldosereductase inhibitor (ARI), an angiotensin converting enzyme (ACE)inhibitor or an angiotensin II (AII) antagonist which combinations areuseful in the prevention and treatment of the complications of diabetes.

3-Hydroxy-3-methylglutaryl Coenzyme A (HMG Co A) reductase inhibitorseffectively inhibit cholesterol synthesis in the liver throughstimulation of the low density lipoprotein (LDL) receptors. These drugsare currently pre-eminent in the treatment of all hypercholesterolaemia,except the relatively rarely occurring homozygous familialhypercholesterolaemia. Therapy with HMG Co A-reductase inhibitors mayresult in regression of atherosclerotic vascular lesions and several HMGCo A-reductase inhibitors have proven to reduce mortality. Various HMGCo A-reductase inhibitors are marketed, and are collectively referred toas ‘statins’.

We have discovered that statin drugs, in particular(E)-7-[4-(4-fluorophenyl)-6-isopropyl-2-[methyl(methylsulfonyl)amino]pyrimidin-5-yl](3R,5S)-3,5-dihydroxyhept-6-enoicacid or a pharmaceutically acceptable salt thereof (the AGENT), thecalcium salt of which is shown in FIG. 1 below, and atorvastatin producean improvement in the nerve conduction velocity (NCV) and nerve bloodflow in an animal model of diabetic neuropathy. Therefore, statin drugsmay be used to improve diabetic neuropathy, whether in type I or type IIdiabetes.

Therefore we present as a first feature of the invention a method fortreating neuropathy in a patient suffering from diabetes comprisingadministering to the patient a statin drug.

As a preferred feature of the invention we present a method forimproving nerve conduction velocity and/or nerve blood flow in a patientsuffering diabetic neuropathy comprising administering to the patient astatin drug.

Further features of the invention include use of a statin drug in thepreparation of a medicament for use in the treatment of any of theconditions mentioned above.

Examples of statin drugs include, for example, pravastatin (PRAVACHOL™),lovastatin (MEVACOR™), simvastatin (ZOCOR™), cerivastatin (LIPOBAY™),fluvastatin (LESCOL™), atorvastatin (LIPITOR™) and the AGENT, thestructures of which are shown in FIG. 1. Preferably the statin drug isatorvastatin or the AGENT. Preferably the AGENT is used at a dose of 5to 80 mg per day.

The AGENT is disclosed in European Patent Application, Publication No.0521471, and in Bioorganic and Medicinal Chemistry, (1997), 5(2),437-444 as an inhibitor of 3-hydroxy-3-methylglutaryl CoA reductase(HMG-CoA reductase). Preferably the calcium salt is used as illustratedin FIG. 1.

Atorvastatin is disclosed in U.S. Pat. No. 5,273,995; lovastatin isdisclosed in U.S. Pat. No. 4,231,938; simvastatin is disclosed U.S. Pat.No. 4,450,171 and U.S. Pat. No. 4,346,227; pravastatin is disclosed inU.S. Pat. No. 4,346,227; fluvastatin is disclosed in U.S. Pat. No.4,739,073; cerivastatin is disclosed in U.S. Pat. No. 5,177,080 and U.S.Pat. No. 5,006,530.

Other compounds which have inhibitory activity against HMG-CoA reductasecan be readily identified by using assays well known in the art.Examples of such assays are disclosed in U.S. Pat. No. 4,231,938 atcolumn 6 and WO84/02131 at pages 30-33.

It will be appreciated that the statin drug may be administered inaccordance with the invention in combination with other drugs used fortreating diabetes or the complications of diabetes, such as neuropathy,nephropathy, retinopathy and cataracts. Examples of such treatmentsinclude insulin sensitising agents, insulin and oral hypoglycaemics(these are divided into four classes of drug—sulfonylureas, biguanides,prandial glucose regulators and alpha-glucosidase inhibitors). Examplesof insulin sensitising agents include, for example, troglitazone,rosiglitazone, pioglitazone, MCC-555,(S)-2-ethoxy-3-[4-(2-{4-methanesulfonyloxyphenyl}ethoxy)phenyl]propanoicacid and3-{4-[2-(4-tert-butoxycarbonylaminophenyl)ethoxy]phenyl}-(S)-2-ethoxypropanoic acid. Examples of sulfonylureas are glimepiride,glibenclamide, gliclazide, glipizide, gliquidone and tolazamide. Anexample of a biguanide is metformin. An example of an alpha-glucosidaseinhibitor is acarbose. An example of a prandial glucose regulator isrepaglinide.

Other treatments are known also to improve NCV in diabetic neuropathyand as such these represent preferred combinations of the invention.Examples of such treatments include aldose reductase inhibitors, ACEinhibitors and AII antagonists.

The use of aldose reductase inhibitors or ACE inhibitors in improvingNCV and treating diabetic neuropathy is disclosed in PCT/GB98/01959. Theuse of AII antagonists in improving NCV and treating diabetic neuropathyis disclosed in WO93/20816.

Suitable aldose reductase inhibitors include, for example, epalrestat,tolrestat, ponolrestat, zopolrestat, AD-5467, SNK-860, ADN-138, AS-3201,zenarestat, sorbinil, methosorbinil, imirestat and minalrestat(WAY-121509).

Suitable ACE inhibitors include, for example, benazepril, benazeprilat,captopril, delapril, fentiapril, fosinopril, imidopril, libenzapril,moexipril, pentopril, perindopril, pivopril, quinapril, quinaprilat,ramipril, spirapril, spiraprilat, trandolapril, zofenopril, ceronapril,enalapril, indolapril, lisinopril, alacepril, and cilazapril. Apreferred ACE inhibitor includes, for example, lisinopril, or apharmaceutically acceptable salt thereof.

Suitable AII antagonists include, for example, losartan, irbesartan,valsartan and candesartan. A preferred AII antagonist is candesartan.

Independent aspects of the present invention include a pharmaceuticalcombination comprising any one of the statin drugs identified above,preferably the AGENT or atorvastatin, and any one of the named ACEinhibitors identified above, or anyone of the aldose reductaseinhibitors identified above, or any one of the AII antagonistsidentified above. Accordingly, further independent aspects of thepresent invention include the following:

(1) A pharmaceutical combination comprising the AGENT and lisinopril;(2) A pharmaceutical combination comprising atorvastatin and lisinopril;(3) A pharmaceutical combination comprising fluvastatin and lisinopril;(4) A pharmaceutical combination comprising pravastatin and lisinopril;(5) A pharmaceutical combination comprising cerivastatin and lisinopril;(6) A pharmaceutical combination comprising the AGENT and candesartan;(7) A pharmaceutical combination comprising the AGENT, or atorvastatin,and(S)-2-ethoxy-3-[4-(2-{4-methanesulfonyloxyphenyl}ethoxy)phenyl]propanoicacid or3-{4-[2-(4-tert-butoxycarbonylaminophenyl)ethoxy]phenyl}-(S)-2-ethoxypropanoic acid

The ‘pharmaceutical combination’ may be achieved by dosing eachcomponent drug of the combination to the patient separately inindividual dosage forms administered together or sequentially.Alternatively the ‘pharmaceutical combination’ may be together in thesame unit dosage form.

Therefore, as a further aspect of the invention we represent apharmaceutical composition comprising a pharmaceutical combination asdescribed herein above together with a pharmaceutically acceptablecarrier and/or diluent.

Independent aspects of the present invention include a pharmaceuticalcomposition comprising any one of the statin drugs identified above,preferably the AGENT or atorvastatin, and any one of the named ACEinhibitors identified above, or any one of the aldose reductaseinhibitors identified above, or any one of the AII antagonistsidentified above together with a pharmaceutically acceptable carrierand/or diluent. Accordingly, further independent aspects of the presentinvention include the following:

(1) A pharmaceutical composition comprising the AGENT and lisinopril;(2) A pharmaceutical composition comprising atorvastatin and lisinopril;(3) A pharmaceutical composition comprising fluvastatin and lisinopril;(4) A pharmaceutical composition comprising pravastatin and lisinopril;(5) A pharmaceutical composition comprising cerivastatin and lisinopril;(6) A pharmaceutical composition comprising AGENT and candesartan; and(7) A pharmaceutical composition comprising the AGENT, or atorvastatin,and(S)-2-ethoxy-3-[4-(2-{4-methanesulfonyloxyphenyl}ethoxy)phenyl]propanoicacid or3-{4-[2-(4-tert-butoxycarbonylaminophenyl)ethoxy]phenyl}-(S)-2-ethoxypropanoic acid; and

-   -   together with a pharmaceutically acceptable carrier and/or        diluent.

A preferred pharmaceutical composition of the invention comprises theAGENT or atorvastatin and an ACE inhibitor (including any one of the ACEinhibitors specifically named above, in particular lisinopril), togetherwith a pharmaceutically acceptable carrier and/or diluent.

A preferred pharmaceutical composition of the invention comprises theAGENT or atorvastatin and an aldose reductase inhibitor (including anyone specifically named above), together with a pharmaceuticallyacceptable carrier and/or diluent.

A preferred pharmaceutical composition of the invention comprises theAGENT or atorvastatin and an AII antagonist (including any onespecifically named above and preferably candesartan), together with apharmaceutically acceptable carrier and/or diluent.

The pharmaceutical compositions of the present invention may beadministered in a standard manner for example by oral or parenteraladministration, using conventional systemic dosage forms, such as atablets, capsules, pills, powders, aqueous or oily solutions orsuspensions, emulsions, sterile injectable aqueous or oily solutions orsuspensions. These dosage forms will include the necessary carriermaterial, excipient, lubricant, buffer, bulking agent, anti-oxidant,dispersant or the like. In particular, compositions for oraladministration are preferred.

The dose of a statin drug, an aldose reductase inhibitor, an AIIantagonist or an ACE inhibitor which can be administered in accordancewith the present invention depends on several factors, for example theage, weight and the severity of the condition under treatment, as wellas the route of administration, dosage form and regimen and the desiredresult, and additionally the potency of the statin drug, aldosereductase inhibitor, AII antagonist and ACE inhibitor employed in thecomposition. In addition, account should be taken of the recommendedmaximum daily dosages for the ACE inhibitors.

Prolonged administration of an ACE inhibitor at a therapeuticallyeffective dose may be deleterious or give rise to side effects incertain patients, for example it may lead to significant deteriorationof renal function, induce hyperkalemia, neutropenia, angioneuroticoedema, rash or diarrhoea or give rise to a dry cough. Administration ofan ARI may also give rise to deleterious effects or side effects at thedose required to inhibit the enzyme aldose reductase sufficiently toproduce a significant beneficial therapeutic effect. The presentinvention lessens the problems associated with administration of an ARIor an ACE inhibitor alone and/or provides a means for obtaining atherapeutic effect which is significantly greater than that otherwiseobtainable with the single agents when administered alone. Furthermore,diabetic neuropathy involve a complex mechanism or number of mechanisms,which initiate a cascade of biochemical alterations that in turn lead tostructural changes. These may result in a diverse patient population.The present invention therefore provides the additional advantage thatit allows tailoring of treatment to the needs of a particular patientpopulation.

The combination of a statin, preferably atorvastatin or the AGENT, withand ACE inhibitor, preferably lisinopril, is either additive orsynergistic in effect in the treatment of neuropathy, in particular NCVor nerve blood flow, in diabetic patients.

The combination of a statin, preferably atorvastatin or the AGENT, withand MI antagonist, preferably candesartan, is either additive orsynergistic in effect in the treatment of neuropathy, in particular NCVor nerve blood flow, in diabetic patients.

A unit dosage formulation such as a tablet or capsule will usuallycontain, for example, from 1 mg to 100 mg of the statin drug, or/andfrom 0.1 mg to 500 mg of an aldose reductase inhibitor, or/and from 0.1mg to 500 mg of an ACE inhibitor. Preferably a unit dose formulationwill contain 5 to 80 mg of the statin drug, or/and 0.1 to 100 mg of analdose reductase inhibitor, or/and 0.1 mg to 100 mg of an AII antagonistor/and 0.1 to 100 mg of an ACE inhibitor.

The present invention covers the pharmaceutical combination of (orproduct containing) the statin and an aldose reductase inhibitor, an AIIantagonist or an ACE inhibitor for simultaneous, separate or sequentialuse in the treatment of diabetic neuropathy. In one aspect of thepresent invention, the AGENT drug and the aldose reductase inhibitor orAII antagonist or ACE inhibitor is presented in admixture in onepharmaceutical dosage form. In another aspect, the present inventioncovers the administration of separate unit dosages of the AGENT andaldose reductase inhibitor or AII antagonist or ACE inhibitor in orderto achieve the desired therapeutic effect. Such separate unit dosagesmay be administered concurrently or sequentially as determined by theclinician. The present invention also covers an agent for the treatmentof diabetic neuropathy comprising a pharmaceutically acceptable carrierand/or diluent and, as active agents, a statin drug, preferably theAGENT or atorvastatin, and an aldose reductase inhibitor or an AIIantagonist or an ACE inhibitor in quantities producing a synergistictherapeutic effect.

In another aspect of the invention there is provided a combination ofpharmaceutical compositions for combination therapy of diabeticneuropathy, the combination consisting of a pharmaceutical compositioncomprising the statin drug and a pharmaceutical composition comprisingan aldose reductase inhibitor or a pharmaceutical composition comprisingan AII antagonist or a pharmaceutical composition comprising an ACEinhibitor.

A further aspect of the present invention comprises the use of a statindrug and an aldose reductase inhibitor or an AII antagonist or an ACEinhibitor in the preparation of a pharmaceutical composition for use inthe treatment of diabetic neuropathy.

A further aspect of the present invention is a method for treatingdiabetic neuropathy wherein a therapeutically effective amount of astatin drug in combination with an aldose reductase inhibitor or an AIIantagonist or an ACE inhibitor is administered systemically, such asorally or parenterally. Where the patient to be treated is normotensive,the ACE inhibitor or AII antagonist will preferably be administered inamounts below that required to cause a reduction in blood pressure.Where the patient to be treated is hypertensive, the ACE inhibitor orAII antagonist will preferably be used in amounts usually employed totreat hypertension.

The effect of a pharmaceutical composition of the present invention maybe examined by using one or more of the published models of diabeticneuropathy well known in the art. The pharmaceutical compositions of thepresent invention are particularly useful for the prevention of,reducing the development of, or reversal of, deficits in nerve functionfound in diabetic patients, and therefore particularly useful in thetreatment of diabetic neuropathy. This may be demonstrated, for example,by measuring markers such as nerve conduction velocity, nerve bloodflow, nerve evoked potential amplitude, quantitative sensory testing,autonomic function testing and morphometric changes. Experimentally,studies analogous to those described in Diabetologia, 1992, Vol. 35,pages 12-18 and 1994, Vol. 37, pages 651-663 may be carried out.

A further aspect of the present invention is a method of treating orpreventing the development of disease conditions associated withimpaired neuronal conduction velocity in a warm-blooded animal(including a human being) requiring such treatment comprisingadministering to said animal a therapeutically effective amount of apharmaceutical combination or composition as described above.

A further aspect of the present invention is a method of reversingimpaired neuronal conduction velocity in a warm-blooded animal(including a human being) requiring such treatment comprisingadministering to said animal a therapeutically effective amount of apharmaceutical combination or composition as described above.

Dosages of the AGENT may be administered according to the cholesterollowering effect desired from a range of 5-80 mg per day in any number ofunit dosages.

Suitable dosages of the statins, ACE inhibitors, aldose reductaseinhibitors or AII antagonists mentioned herein are those which areavailable commercially, and which may be further reduced as suggestedherein, or as advised in such publications as Monthly Index of MedicalSpecialities (P.O. BOX 43, Ruislip, Middlesex, UK).

The following non-limiting Examples serve to illustrate the presentinvention.

EXAMPLE 1

Suitable pharmaceutical compositions of an aldose reductase inhibitor(ARI) include the following:

mg/tablet Tablet 1 ARI 100 Lactose Ph. Eur. 182.75 Croscarmellose sodium12.0 Maize starch paste (5% w/v paste) 2.25 Magnesium stearate 3.0Tablet 2 ARI 50 Lactose Ph. Eur. 223.75 Croscarmellose sodium 6.0 Maizestarch 15.0 Polyvinylpyrrolidone (5% w/v paste) 2.25 Magnesium stearate3.0 Tablet 3 ARI 1.0 Lactose Ph. Eur. 93.25 Croscarmellose sodium 4.0Maize starch paste (5% w/v paste) 0.75 Magnesium stearate 1.0 Capsule 1ARI 10 Lactose Ph. Eur. 488.5 Magnesium stearate 1.5

EXAMPLE 2

Suitable pharmaceutical compositions of an ACE inhibitor include thefollowing:

Tablet 1 ACE Inhibitor 100 Corn starch 50 Gelatin 7.5 Microcrystallinecellulose 25 Magnesium stearate 2.5 Tablet 2 ACE inhibitor 20Pregelatinised starch 82 Microcrystalline cellulose 82 Magnesiumstearate 1

EXAMPLE 3

Capsule mg The AGENT 5.0 Lactose 42.5 Corn starch 20.0 Microcrystallinecellulose 32.0 Pregelatinised starch 3.3 Hydrotalcite 1.1 Magnesiumstearate 1.1

Capsules containing 1, 2.5 or 10 mg of the Agent may be obtainedsimilarly using more or less lactose as appropriate, to achieve a fillweight of 105 mg.

EXAMPLE 4

Suitable pharmaceutical compositions containing the AGENT and an ACEinhibitor in a single dosage form include the following:

Capsule mg The AGENT 5.0 Lisinopril 10.0 Lactose 42.5 Corn starch 20.0Microcrystalline cellulose 32.0 Pregelatinised starch 3.3 Hydrotalcite1.1 Magnesium stearate 1.1

EXAMPLE 5

A patient requiring treatment for diabetic neuropathy is treated withthe AGENT (10 mg) and lisinopril (10 mg). Lisinopril is administeredtwice daily and the AGENT is administered once daily.

EXAMPLE 6

Male Sprague-Dawley rats, 19 weeks old at the start of the study, weredivided into non-diabetic animals (normal control group) and animalsrendered diabetic by intraperitoneal administration of streptozotocin,(40-45 mg/kg, freshly dissolved in sterile saline). Diabetes wasverified 24 hours later by estimating hyperglycaemia and glucosuria(Visidex II and Diastix; Ames, Slough, UK). Diabetic rats were testedweekly and weighed daily. Animals were rejected if the plasma glucoseconcentration was <20 mM of if body weight consistently increased over 3days. Samples were taken from the tail vein or carotid artery afterfinal experiments for plasma glucose determination (GOD-Perid method;Boehringer Mannheim, Mannheim, Germany). After 6 weeks of untreateddiabetes, groups of rats were treated for a further 2 weeks with theAGENT, dissolved in the drinking water.

At the end of the treatment period, rats were anaesthetised withthiobutabarbitone by intraperitoneal injection (50-100 mg/kg). Thetrachea was cannulated for artificial ventilation and a carotid cannulawas used to monitor mean systemic blood pressure.

Motor nerve conduction velocity was measured (as previously described byCameron et al, Diabetologia, 1993, Vol. 36, pages 299-304) betweensciatic notch and knee in the nerve branch to tibialis anterior muscle,which is representative of the whole sciatic nerve in terms ofsusceptibility to diabetes and treatment effects.

Sensory conduction velocity in saphenous nerve was measured between thegroin and ankle (as previously described by Cameron et al. QuarterlyJournal of Experimental Physiology, 1989, vol. 74, pages 917-926).

Sciatic blood flow was measured by hydrogen clearance microelectrodepolarography (as described by Cameron et al., Diabetologia, 1994, vol.37, pages 651-663). The nerve was exposed between the sciatic notch andthe knee and the skin around the incision was sutured to a metal ring toform a pool that was filled with paraffin oil that was maintained at35-37° C. by radiant heat. A glass-insulated platinum micro-electrodewas inserted into the middle portion of the sciatic nerve and polarisedat 250 mV with respect to a subcutaneous reference microelectrode. 10%Hydrogen was added to the inspired gas, the proportions of nitrogen andoxygen being adjusted to 70% and 20% respectively. When the hydrogencurrent recorded by the electrode had stabilised, indicating equilibriumwith arterial blood, the hydrogen supply was shut off and nitrogensupply was increased appropriately. The hydrogen clearance curve wasrecorded until a baseline, defined as no systematic decline in electrodecurrent over 5 minutes. To estimate blood flow, clearance curves weredigitised and exponential curves were fitted to the data by computerusing non-linear regression. The best fitting exponent gave a measure ofnerve blood flow.

Data

All data expressed as group mean±SEM (number of rats used in brackets)

Sciatic Nerve Motor Conduction Velocity

Control Values Non-diabetical control 64.04 ± 0.46 (10) 8 weekdiabetic + vehicle 50.35 ± 0.93 (6) Atorvastatin 9Diabetic + 2 weeks ofdosing at 20 mg/kg 61.53 ± 0.76 (6) Diabetic + 2 weeks of dosing at 50mg/kg 63.59 ± 0.69 (6) The AGENT Diabetic + 2 weeks of dosing at 20mg/kg 63.34 ± 0.61 (8) Dose response determination 5 groups of 8 rats -dose ranged from 0.3-20 mg/kg - ED₅₀ = 2.3 mg/kg

Saphenous Nerve Sensory Conduction Velocity

Control Values Non-diabetic control 61.09 m/s ± 0.67 (10) 8 weekdiabetic + vehicle 52.77 m/s ± 0.79 (6) Atorvastatin Diabetic + 2 weeksof dosing at 20 mg/kg 59.77 m/s ± 0.93 (6) Diabetic + 2 weeks of dosingat 50 mg/kg 60.72 m/s ± 0.94 (6) The AGENT Diabetic + 2 weeks of dosingat 20 mg/kg 60.57 m/s ± 0.83 (8) Dose response determination 5 groups of8 rats - dose ranged from 0.3-20 mg/kg - ED₅₀ = 0.9 mg/kg

Sciatic Nerve Blood Flow

Control Values Non-diabetic control 17.89 ml/min/100 g (of nerve tissue)± 0.65 (10) 8 week diabetic + 8.82 ml/min/100 g ± 0.56 (10) vehicleAtorvastatin Diabetic + 2 weeks of 16.96 ± 1.39 ml/min/100 g (6) dosingat 50 mg/kg The AGENT Diabetic + 2 weeks of 16.19 ± 0.51 ml/min/100 g(8) dosing at 20 mg/kg

1-17. (canceled)
 18. A pharmaceutical combination comprising(E)-7-[4-(4-fluorophenyl)-6-isopropyl-2-[methyl(methylsulfonyl)amino]pyrimidin-5-yl](3R,5S)-3,5-dihydroxyhept-6-enoicacid or a pharmaceutically acceptable salt thereof and candesartan.19-21. (canceled)
 22. A pharmaceutical composition comprising(E)-7-[4-(4-fluorophenyl)-6-isopropyl-2-[methyl(methylsulfonyl)amino]pyrimidin-5-yl](3R,5S)-3,5-dihydroxyhept-6-enoicacid or a pharmaceutically acceptable salt thereof, candesartan and apharmaceutically acceptable diluent or carrier.
 23. A unit dosageformulation comprising a pharmaceutical combination according to claim18.
 24. A unit dosage formulation comprising a pharmaceuticalcomposition according to claim
 22. 25. The unit dosage formulation ofclaim 18 or claim 22 wherein the(E)-7-[4-(4-fluorophenyl)-6-isopropyl-2-[methyl(methylsulfonyl)amino]pyrimidin-5-yl](3R,5S)-3,5-dihydroxyhept-6-enoicacid or a pharmaceutically acceptable salt thereof is present in saidformulation in an amount of from 5 to 80 mg, and the candesartan ispresent in an amount of from 0.1 to 100 mg.